Drug reference

Clindamycin

Lincosamide · Antibiotic

Also known as Clindamycin Hydrochloride, Clindamycin Phosphate, Clindamycin Palmitate

START

Confirm serious bacterial infection where penicillin inappropriate. Rule out less toxic alternatives. Reserve for penicillin-allergic patients or serious anaerobic infections. NOT for viral URIs.

TYPICAL MAX

1.8 g/day oral; 4.8 g/day IV. Do not use for non-bacterial infections.

STOP IF

Severe/watery diarrhea (suspect CDAD), severe hypersensitivity (SJS/TEN/anaphylaxis), agranulocytosis

WATCH

Diarrhea pattern (frequency, character — watery/bloody), C. difficile PCR/toxin if diarrhea develops, LFTs if prolonged therapy, rash

CDSCO approvedSchedule HJan AushadhiATC J01FF01

Dose laddermg/d

Renal dose adjustmenteGFR mL/min/1.73m²

KDIGO 2024 + manufacturer label

Pharmacokineticsplasma · t hours

ONSET: 1h · 45-60 min (oral peak)
PEAK: 1h · 45-60 min (oral); 1-3 h (IM)
t½: 2.5h · 2.4 h (range 2-3 h)
DURATION: 8h · 6-8 h (q6-8h dosing)

EXCRETION

~10% renal unchanged; 3.6% fecal; hepatic metabolism; NOT

route + CYP

INTERACTIONS

4 major

incl. contraindicated

PREGNANCY

FDA PLLR: Animal studies showed no teratogenicity. Limited human data. Crosses placenta. Use only if clearly needed and benefit outweighs risk. Generally considered safe in pregnancy (old Category B).

FDA category + note

Top interactionssee all 12 →

Eikenella CorrodensContraindicatedTextbookHarrison 22e · p1054
Pasteurella MultocidaContraindicatedTextbookHarrison 22e · p1054
Neuromuscular Blockers (e.g., Vecuronium, Rocuronium)SevereDatabase
Neuromuscular Blocking Agents (e.g., Atracurium, Vecuronium)SevereDatabase

Available in India

408 branded formulations and 468 fixed-dose combinations. Look up specific brands in the Drugs workspace.

Jan Aushadhi — generic available at GoI pharmacies

Mechanism

Clindamycin is a lincosamide antibiotic that inhibits bacterial protein synthesis by binding to the 23S ribosomal RNA of the 50S subunit of the bacterial ribosome. This binding prevents peptide bond formation and translocation of the nascent peptide chain, effectively halting protein synthesis. It is primarily bacteriostatic but may be bactericidal against susceptible organisms at high concentrations. Its three-dimensional structure resembles the 3'-ends of L-Pro-Met-tRNA and deacylated-tRNA during the peptide elongation cycle, acting as a structural analog that impairs peptide chain initiation.

Indications

Serious anaerobic bacterial infections (Bacteroides, Clostridium, Peptostreptococcus)Serious respiratory tract infections (empyema, anaerobic pneumonitis, lung abscess)Serious skin and skin structure infections (Streptococcus pyogenes, Staphylococcus aureus, anaerobes)Intra-abdominal infections (peritonitis, intra-abdominal abscess)Gynecologic infections (endometritis, tubo-ovarian abscess, pelvic cellulitis)Septicemia (S. aureus, streptococci, anaerobes)Bone and joint infections (acute hematogenous osteomyelitis, adjunctive therapy)Acne vulgaris (topical)

Dosing

Adult: Oral: 150-450 mg PO q6-8h (max 1.8 g/day). IV/IM: 600-1200 mg/day divided q6-12h (max 4.8 g/day IV for severe infections). C. difficile infection: 300 mg PO QID x 10-14 days (alternative to metronidazole/vancomycin).
Pediatric: Oral: 8-25 mg/kg/day divided q6-8h (max 1.8 g/day). IV/IM: 20-40 mg/kg/day divided q6-8h (max 4.8 g/day). Neonates <1 month: 5 mg/kg IV q8-12h.
Renal adjustment: No adjustment required (not renally eliminated; hemodialysis and peritoneal dialysis are NOT effective in removing clindamycin).
Hepatic adjustment: Severe hepatic impairment: monitor serum levels if available; may need dose reduction. No adjustment for mild-moderate hepatic impairment.
Geriatric: No specific adjustment; monitor for C. difficile diarrhea and renal function if co-morbid.
Max dose: 1.8 g/day (oral); 4.8 g/day (IV); 600 mg/dose (IV)

Pharmacokinetics

Onset

Rapid bacteriostatic effect; clinical improvement typically within 48-72 hours.

Peak effect

Oral: peak plasma at 45-60 minutes. IM: peak at 1-3 hours. IV: immediate distribution.

Duration

6-8 hours (supports q6-8h dosing).

Half-life

2.4 hours (range 2-3 hours; may be prolonged in severe hepatic impairment).

Bioavailability

~90% (oral).

Protein binding

60-94% (concentration-dependent; bound primarily to alpha-1-acid glycoprotein).

Metabolism

Hepatic via CYP3A4 (primary) and CYP3A5. Inactive metabolites: clindamycin sulfoxide (oxidative) and N-desmethylclindamycin (N-demethylated). Active metabolites also formed but primarily inactive forms predominate.

Excretion

Urine: ~10% unchanged + metabolites within 24 hours. Feces: ~3.6% unchanged. Remainder as inactive metabolites via biliary/enterohepatic route. Not dialyzable.

Contraindications

Hypersensitivity to clindamycin or lincomycin
History of pseudomembranous colitis or ulcerative colitis
Non-bacterial infections (e.g., most upper respiratory tract infections)
Meningitis (does not adequately penetrate CSF)

Side effects

Common

Diarrhea (mild, self-limited)Nausea, vomiting, abdominal painUnpleasant/metallic taste (oral/IV)Maculopapular rashEsophagitis/esophageal ulcer (oral capsules — take with water, remain upright)

Serious

Clostridioides difficile-associated diarrhea (CDAD) — FDA BLACK BOX WARNING: ranging from mild diarrhea to fatal pseudomembranous colitis. Can occur up to 2 months after discontinuation.
Severe hypersensitivity (anaphylaxis, angioedema)
Severe cutaneous adverse reactions (SJS, TEN, DRESS, AGEP)
Hepatotoxicity (jaundice, elevated transaminases)
Neutropenia, agranulocytosis, thrombocytopenia
Polyarthritis

Pregnancy & lactation

Pregnancy

Lactation

Excreted in breast milk (0.5-1.5% of maternal dose). May cause diarrhea or candidiasis in nursing infant. Monitor infant for GI upset. Compatible per AAP with monitoring.

Drug interactions

Eikenella Corrodens

Contraindicated

Textbook

ineffective treatment

Eikenella corrodens is resistant to clindamycin but sensitive to trimethoprim-sulfamethoxazole and fluoroquinolones. Amoxicillin-clavulanate, ampicillin-sulbactam, and cefoxitin are good choices for human bite infections.

Source: Harrison 22e · p1054

Pasteurella Multocida

Contraindicated

Textbook

ineffective treatment

Pasteurella multocida is resistant to clindamycin; other β-lactam antimicrobial agents, quinolones, tetracycline, and erythromycin are sensitive. Amoxicillin-clavulanate, ampicillin-sulbactam, and cefoxitin are good choices.

Source: Harrison 22e · p1054

Neuromuscular Blockers (e.g., Vecuronium, Rocuronium)

Severe

Database

Prolonged respiratory depression, apnea, muscle weakness

Monitor closely for respiratory depression and muscle weakness. Reduce neuromuscular blocker dose if co-administration is unavoidable. Be prepared for respiratory support.

Neuromuscular Blocking Agents (e.g., Atracurium, Vecuronium)

Severe

Database

Prolonged respiratory depression and paralysis

Avoid concomitant use if possible. If unavoidable, monitor closely for respiratory depression and be prepared for ventilatory support. Adjust dose of neuromuscular blocker as needed.

Amoxicillin

Moderate

Textbook-cited

Reduced antibacterial efficacy; therapeutic failure.

Avoid concurrent use of bacteriostatic and bactericidal antibiotics

Source: KDT 7e · p949

Ampicillin

Moderate

Textbook-cited

Reduced antibacterial efficacy; therapeutic failure.

Avoid concurrent use of bacteriostatic and bactericidal antibiotics

Source: KDT 7e · p949